Method and apparatus for the automatic regulation of boturating devices



Dec. 7, 1965 L. A. TURNER ,504

METHOD AND APPARATUS FOR THE AUTOMATIC REGULATION OF OBTURATING DEVICES Filed April 24, 1961 6 Sheets-Sheet 1 mar- ATTORNEYS Dec. 7, 1965 L. A. TURNER 3,221,504

METHOD AND APPARATUS FOR THE AUTOMATIC REGULATION OF OBTURATING DEVICES Filed April 24, 1961 6 Sheets-Sheet 2 LAWREA/Cf A. TUEA/EE 5r MWPM/i Dec. 7, 1965 L. A. TURNER METHOD AND APPARATUS FOR THE AUTOMATIC REGULATION OF OBTURATING DEVICES 6 Sheets-Sheet 5 Filed April 24, 1961 [AWE/m5 14 Md ufimAA/L I AT/YIKNEVS Dec. 7, 1965 Filed April 24, 1961 L. A. METHOD AND APPARATUS FOR THE AUTOMATIC REGULATION OF OBTURATING DEVICES TURNER 3,221,504

6 Sheets-Sheet 4 ad ld fie. 3.

5 8 7 3 0 25 L58. lid /3 AT L l/VVfN/OE AT ORNEYS Dec. 7, 1965 1.. A. TURNER 3,221,504

METHOD AND APPARATUS FOR THE AUTOMATIC REGULATION OF OBTURATING DEVICES Filed April 24, 1961 6 Sheets-Sheet 5 /d 7 2 66 Ha Ba INVENTOR. LAWRENCE A. rum/m 7, 1965 A. TURNER 3,221,504

METHOD AND APPARATUS FOR THE AUTOMATIC REGULATION OF OBTURATING DEVICES Filed April 24, 1961 6 Sheets-Sheet e l/Wf/WOE LAWRENCE A. TU/P/VE/F ATTU/FNEYS United States Patent 3,221,504 METHOD AND APPARATUS FOR THE AUTO- MATlC REGULATION OF OBTURATING DEVICES Lawrence Alexander Turner, Middleton, Cape Province, Republic of South Africa, assignor to Fluid Dynamics (Proprietary) Limited, Port Elizabeth, Republic of South Africa Filed Apr. 24, 1961, Ser. No. 105,140 Claims priority, application Republic of South Africa, Apr. 29, 1960, 1,741/60 It] Claims. (Cl. 61-22) This invention relates to a method and apparatus for the automatic regulation of obturating devices used for controlling the outflow of water from an open body of water impounded by a barrier, such as diversion weirs, dams, reservoirs and the like, particularly in cases where the flow of water in the river or stream feeding the weir or the like is sporadic and the level of the body of water therefore varies.

In the art of irrigation, it is often necessary to control the discharge of water from a weir, dam, reservoir or the like to an irrigation canal, by means of an obturating device such as a radial gate, a drum gate, a sector weir or a plain vertical sliding gate valve, so that flow will take place when sufficient water is stored above the weir or in the dam or the like and which obturating device is required to be closed at times when the flow of water into the storage space of the weir or the like, is less than what is suflicient for irrigation purposes. The invention envisages a method and apparatus to provide accurate and entirely automatic control of the discharge of water from a weir or the like into a canal, without recourse to human supervision or to elaborate float switches, powered hoists, counterbalances or other equipment associated with automatic operation of obturating devices presently used for this purpose.

In the case of a diversion weir provided across a river, the obturating device, hereinafter referred to as a gate, must fulfil the following requirements:

(1) The gate must remain closed until the water level reaches a predetermined height in the Weir which is well above the level of the discharge canal. This ensures that the floating trash and debris which often accompanies the first rush of water after a rain storm in the catchment area of the river feeding the weir, is not drawn directly into the canal. In the event of weak river flows, particularly at night, it must also ensure that maximum use is made of the storage capacity of the weir but without spilling water over the crest.

(2) As soon as the required level is reached, the gate must open automatically to a minimum predetermined amount depending on the level which the water in the weir must reach before the gate opens at all, and it must then deliver the predetermined flow of water to the canal for as long as the level of water in the weir lies between certain specified upper and lower limits. When the level drops below the lower limit the gate must close completely.

(3) If the water in the weir rises to such an extent that the gate delivers an excessive flow to the canal, the device must automatically close the gate. It should open the gate automatically as soon as the river subsides to an acceptable level.

(4) When the flow ceases in the river, the device must ensure that the weir is full before the gate opens, so that irrigation can take place at a later date when required.

The apparatus according to the present invention, which is for the automatic regulation of the outflow from an open body of water impounded by a barrier, such as a weir, and having a varying level when the level of said body of water is below a predetermined upper limit, com

prises a gate which is contiguous to said body of water and is arranged to be opened and closed to control the outflow of water from the body of water. The gate has a hollow float coupled to the side of the gate facing the body of water, and has a water inlet adjacent its bottom and an air vent at its top. Conduit means are connected to and open out of the float and discharge downstream of the barrier. Control means are connected in series with the conduit means and control the withdrawal of water from the float at varying controlled rates so as to vary the buoyancy of the flow and consequently the opening and closing movements of the gate. This control means is operatively dependent on the level of the impounded body of water, and comprises at least one syphon having a throat.

The operation of the syphon means is arranged to be controlled by the provision of air inlet means for syphon breaking purposes connected to the throat or throats thereof, the admission of air being arranged to be dependent upon the level of water in the weir in relation to the level of the air inlet means. These air inlet means also act as priming vents for the syphon means. The syphon means are so arranged that when the level of water in the weir falls to a predetermined low level, suflicient water is allowed to enter the float to cause the gate to close, and when the water level in the weir is at a predetermined higher level the float is either emptied or permitted partly to fill with water, whereby, due to its buoyancy, it causes the gate to open and remain open. Furthermore, when the level of the water in the weir rises above a predetermined maximum level due to flood water, the float is arranged to fill with water via its top air vent and thereby to sink and cause the gate to close and remain closed until the level of water in the weir falls sufliciently to uncover the air vent of the float.

According to a preferred arrangement, two separate syphons are provided, one of which, termed the main syphon, has a discharge capacity when primed capable of removing water from the float at a rate in excess of the capacity of the water inlet means adjacent the bottom of the float, so as thereby to cause rapid emptying of the float notwithstanding the continued inflow of Water via such water inlet means, while the other syphon, termed the secondary syphon, has a discharge capacity which is substantially equal to the capacity of the Water inlet means adjacent the bottom of the float.

The air inlet means for syphon breaking and priming of the main syphon, has its opening arranged slightly below the corresponding opening of the equivalent air inlet and priming means connected to the secondary syphon so that raising of the level of water in the weir causes the main syphon to prime before the secondary syphon. Hereinafter, this air inlet and priming means will be referred to as the priming vent. In both cases, when the upstream or suction inlets of the two syphons are arranged to rise and fall with the float, the throats of the two syphons are arranged below their respective priming vents, when the float is in its lowest position.

In the case where the two syphons are fixed, then this arrangement will remain unaltered whatever position the float is in.

In the case where the syphons are arranged to rise and fall with the float, both priming vents are connected to the throats of their respective syphons by flexible conduit means such as a hose pipe to allow for the rising and falling movements of the float. The throats of both syphons Will be at atmospheric pressure and they will therefore spill over only the amount of water entering at the water inlet means at the bottom of the float.

For convenience, the secondary syphon pipe may be located within the bore of the main syphon pipe.

The end of the suction limb of the secondary syphon terminates closer to the bottom of the float than the end of the suction limb of the main syphon, whereby under certain circumstances, the secondary syphon will continue operating after the main syphon has stopped operating.

It will be understood that the float is attached to the upstream side of the gate. The air vent at the top side of the float is arranged to have a water inlet capacity substantially greater than the combined capacities of both syphons or other means used for withdrawing water from the float. Stop means are provided to limit the extent to which the float will rise and consequently thereby to limit the maximum outflow of water past or beneath the open gate.

According to another embodiment of the invention, conduit means from the float is connected to a separate control chamber and the aforementioned water inlet means to permit water to enter the float at the bottom thereof is transferred to the control chamber. In addition the suction limbs of the two syphons are located in this control chamber. By this arrangement water enters and is withdrawn from the float by way of the above mentioned connecting conduit means, whereby the level of water in the float corresponds to the level of water in the control chamher which level is, as before, controlled by the two syphons.

According to still a further embodiment of the invention, conduit means from the float is connected to a separate control chamber and the previously described water inlet means to permit water to enter the float at the bottom thereof, is transferred to the control chamber. In this case the suction limb of a single syphon corresponding to the main syphon, is located in this control chamber and the opening and closing of the lower open end thereof is arranged to be controlled by a float-actuated valve, the float of which is located in the control chamber. The arrangement is such that the lower open end of this suction limb is closed whenever the level of water in the control chamber falls sufficiently to expose the float, the weight of which then acting through a lever to close the valve thus keeping the syphon primed. In this case, the conduit for withdrawing water from and admitting water to the float controlling the gate, enters the control chamber at a level above the float and above the lower valvecontrolled end of the suction limb of the single syphon. As in the case of the two syphon arrangement, this single syphon is also controlled by an air inlet or priming vent connected to the throat thereof. In this arrangement the intermittent phase of operation will of course be eliminated.

To enable the invention to be more clearly understood, reference is now made to the accompanying drawings.

In the drawings:

FIGURE 1 is a diagrammatic sectional side elevation of apparatus constructed according to the invention;

FIGS. la-lf are diagrammatic sectional side elevations illustrating the various operative positions of the apparatus of FIG. 1;

FIGURE 2 is a view similar to that of FIGURE 1, but showing a modified arrangement of the apparatus.

FIGURE 3 is a diagrammatic plan view showing a further modified arrangement of apparatus for carrying out the invention.

FIGURES 4 to 9 are diagrammatic sectional side elevations illustrating the various operative positions of the apparatus of FIGURE 3; and

FIGURE 10 is a similar view illustrating yet a further method of controlling the buoyancy of the float.

Referring to FIGURE 1, reference 1 denotes a barrier in the form of the wall of a weir impounding an open body of water 2 which has a varying level and from which a predetermined flow is required to be discharged into an irrigation canal (not shown) by way of a radial gate 3, which is contiguous to the body of water 2 and pivotally mounted for vertical part-rotatory movement about a hollow pivot axis shaft 4 which is located below the level of the bed of the canal.

Opening and closing of the gate 3 is controlled by means of a hollow float 5 attached to it on the side of the gate toward the body of water 2 as shown. The float 5 is provided with a water inlet 6 adjacent its bottom end and with an air vent 7 at its top end. The upward movement of the float is limited by means of an adjustable stop 8, which thereby limits the maximum opening of the gate 3. The main syphon conduit is indicated at 9 while the secondary syphon conduit 10 is in the form of a pipe located in the bore of the main syphon conduit 9.

As shown, both suction limbs of the syphons are located within the float 5, and their suction inlet ends terminate just above the bottom of the float 5. It is to be noted that the lower end of the suction limb of the main syphon terminates a greater distance above the floor of the float 5, than does the lower end of the suction limb of the secondary syphon 10. For instance, the lower end of the main syphon may terminate four inches above the floor of the float, while the secondary syphon may terminate one inch above said floor. Their outlet ends extend downstream of the weir below the gate 3, as required. A flexible coupling 19 is provided in an outlet pipe 20.

The main syphon has its throat T connected to its priming vent 11, by way of a flexible conduit or tube 12, such as a length of hose piping while the throat T of the secondary syphon is similarly connected to its priming vent 13, by a hose pipe or the like located in the bore of the tube 12. The priming vents 11 and 13 can be fixed at any suitable level below the predetermined upper limit of the level of the water impounded by the weir, the level of the vent 13 being shown in this embodiment as slightly above the level of the vent 11.

As shown, the level of the water impounded by the wall 1 of the weir, is level with the crest thereof, but the crest of the wall 1 could be above the level at which the end of the conduit 12 is fixed. The float 5, has completely filled with water via the aperture 6 whereby the gate 3 is in its fully closed position. It will be noted that both priming vents 11 and 13 are just above water level and the throats T and T of both syphons are therefore at atmospheric pressure. Note also that water from aperture 6 will continue to flow through the syphons but that the air admitted to the throats via the priming vents 11 and 12, prevents priming taking place, so that under these conditions the syphons merely act as spillways.

A slight rise in the water level, which will, in the embodiment shown, result in a flow over the wall 1, will cover the priming vent 11 thereby cutting off the supply of air filling the main syphon with water and causing the main syphon to become primed. Since its capacity is many times the capacity of the water inlet 6 to the float 5, water is rapidly drawn off from the interior of the float 5 which then gains buoyancy and commences to rise thereby opening the gate 3 until it is stopped by the adjustable stop 8 as shown in FIG. 1b.

It should be noted that flexible tube 12 is sufliciently flexible to allow free movement of the gate 3 and float 5 within these limits.

At this stage the secondary syphon is still unprimed and if there is insuflicient water flowing into the weir to maintain the level, this will fall thereby uncovering the priming vent 11 and thus causing the main syphon to break off due to air entering its throat. This will allow the continued inflow of water via the aperture 6, to decrease the buoyancy of the float until it closes.

On the other hand, if the water level in the weir remains constant, the main syphon will empty the float and will then break olf due to air entering through the lower end of the suction limb as shown in FIG. 10.. The float again fills and sinks to close the gate 3. This intermittent filling and emptying phase will continue as long as the level remains constant above the priming vent 11 but below priming vent 13.

This intermittent phase will continue until the water level in the weir rises sufliciently to cover the priming vent 13 of the secondary syphon as shown in FIG. 1e. When this occurs, both syphons will be in a position to become primed as soon as the float reaches its next down position. Both syphons will now be primed and will commence to operate and the float, due to its increased buoyancy will again rise. The main syphon repeats its role of drawing ofl water quickly until the bottom end of its suction limb is uncovered, whereupon it breaks off. Since however, the bottom end of the suction limb of the secondary syphon remains submerged, as shown in FIG. 1d, it will continue to draw off water from the float as fast as it enters via the water inlet aperture 6, and the float will remain buoyant and in its raised position to keep the gate 3 open.

In practice, the fully primed secondary syphon can be designed to handle a reasonable variation in flow to take care of the flow thorugh the water inlet aperture 6, which .will vary slightly according to the head of water in the weir, so that the float will remain'sufliciently buoyant to hold the gate in its open position.

If the water level in the weir continues to rise, it will eventually cover the air vent 7, as shown in FIG. 1 and water will flow through it and will fill the float due to the capacity of the air vent 7 being substantially greater than the combined capacities of both syphons. Note that both secondary and primary syphons would be fully primed and would, in these conditions, discharge continuously.

The gate will then close and will remain closed until the water level in the weir falls sufliciently to stop water from flowing into air vent 7, whereupon the gate will again open due to the action of both syphons as described above.

If however the water level in the weir continues to fall until it uncovers the priming vent 13, the secondary syphon will break off and the float will again sink thus closing the gate 3.

FIGURE la illustrates the condition in which the level A of the water in the weir is below the crest of the wall 1. Water passing into the float 5 by way of water inlet aperture 6 has risen therein to the level A and both main syphon 9 and secondary syphon 10 are acting merely as spillways. The float 5 therefore remains substantially full so that the gate 3 remains closed.

FIGURE 10 illustrates the condition where the rate of inflow into the weir is insufficient to maintain the level shown in FIGURE lb, the level having fallen sufficiently to uncover the priming vent 11 and thereby to cause the I main syphon 9 to break off. Water will then enter the inlet 6 to fill the float 5 which will sink and close the gate 3 which will now remain closed as long as these conditions prevail. 7

FIGURE 2 illustrates a modified arrangement in which both main and secondary syphons, instead of being carried by the float and gate structure, are located as fixtures in any convenient position within or in association with the body of water impounded by the weir. As shown, the main syphon 15 and the secondary syphon 16 are fixed in an upright position with their suction limbs connected by the conduit 17 to the bottom of the float 5 and their discharge limbs connected to a downstream take-off conduit 18 having a flexible coupling 21 adjacent to the shaft 4'. Alternatively their discharge limbs may pass through the shaft 4 which is made hollow for this purpose.

In this case, the throats of the two syphons are connected to their respective priming vents l1 and 13 by short rigid pipes as shown. The operation of the device is the same as that described in FIGURE 1.

In a modified arrangement, the priming vents of both main and secondary syphons may be placed at the same level so that both syphons will be primed simultaneously. This will eliminate the phase when the gate 3 opens and closes intermittently.

The arrangement illustrated in FIG. 2 in which the bot- 6 tom end of the suction limb of the secondary syphon is lower, as regards the bottom of the float, than the suction limb of the main syphon, may be located at the bottom end of the suction limbs at 23 i.e., outside of the float.

The flexible couplings 19 and 21 are of course provided to accommodate free movement of the syphon limbs about the pivot shaft 4. Alternatively the flow may take place via a hollow axis shaft and a hollow bearing.

The screen 24 is provided to protect the inlet aperture 6.

Reference is now made to FIGS. 3 to 9 which illustrate another method of carrying out the invention. In this case a separate control chamber 25 is connected to the float 5 by a conduit 26 and the aforementioned water inlet aperture 6 in the float is dispensed with and instead an equivalent water inlet aperture 6a is provided at or near the bottom of the control chamber 25. A main syphon 15a and a secondary syphon 16a are arranged as shown to withdraw water from the control chamber and discharge it downstream from the weir indicated by the wall 1a. The control chamber 25 is in direct communication with the body of water in the weir with a screen 27 provided across an opening of an outer chamber 28 to exclude the entry of debris. The radial gate 3 controls the discharge of water into a canal 29.

In FIGS. 4 to 9, A indicates the body of water impounded by the weir wall 1a. FIGURE 4 illustrates the conditions in which the level of water in the weir is just below the crest of the wall In. Water passing into the control chamber 25 by way of the water inlet aperture 6a has risen to a level corresponding to the level of water in the weir and both main syphon 15a and secondary syphon 16a are acting as spillways. Water from the control chamber 25 has, by way of the connecting conduit 26, substantially filled the float 5, so that the gate 3 is closed.

FIGURE 5 illustrates the condition when the water level in the weir has risen above the crest of the wall 1a but is still below the level of the priming vent 13a. Main syphon 15a becomes primed and commences to draw water out of the control chamber 25 and consequently out of the float 5 at a rate faster than water can enter via the inlet aperture 6a. This lowers the water level in the control chamber 25 and the float 5 which, thereby gaining buoyancy, rises and opens the gate 3, However as soon as the water level in the control chamber 25 falls sufliciently to uncover the bottom end of suction limb of the main syphon 15a, this syphon ceases to operate and the control 25 and the float 5 again fills with water thereby causing the float 5 to fall and close the gate 3. Under this condition, the gate 3 opens and closes intermittently.

FIGURE 6 illustrates the condition in which the rate of flow into the weir is insufficient to maintain the level shown in FIGURE 5 which has fallen sufficiently to uncover the priming vent 11a and thereby to cause the main syphon 15a to break off. The water entering via the inlet 6a commences to fill up the control chamber 25 and the float 5 which in due course sinks and closes the gate 3, which remains closed.

FIGURE 7 illustrates the condition when the flow of water into the weir remains suflicient to maintain the level of impounded water between the priming vents 11a and 13a. In this case the action continues to be intermittent as described with reference to FIGURE 5.

FIGURE 7 shows the condition just after the main syphon 15a has broken off due to the bottom end of its suction limb having been uncovered by the fall of the level in the control chamber 25.

FIGURE 8 illustrates the condition after the level of water in the weir has risen sufficiently to cover both priming vents 11a and 13a. Both syphons then become primed and the water levels in both the control chamber 25 and the float 5 fall rapidly thereby permitting the float 5 to rise and open the gate 3 to its fullest extent.

FIGURE 8 shows the position just after the main syphon 15a has broken off due to the bottom end of its suction limb having been uncovered. At this stage the secondary syphon 16a continues to operate and, since the rate of inflow via the inlet aperture 6a is equal to the capacity of the secondary syphon 16a, the level of water in the control chamber remains at a low position as indicated, and the gate 3 remains in its fully open position.

FIGURE 9 illustrates the condition when, due to flood water, the level of water in the weir rises still further until the air vent 7 of the float is submerged and water flows rapidly into it causing it to sink and close the gate 3. Although both syphons continue to operate, their combined capacities are less than the combined rate of inflow via the air vent 7 and the inlet aperture 6a, so that the float remains full and the gate 3 remains fully closed. This permits debris, brought down by the flood water, to be swept over the crest of the weir wall In. After the flood has subsided sufliciently, the conditions will usually return to those illustrated by FIGURE 8.

FIGURE 10 illustrates a final alternative arrangement in which float-actuated valve means is used to control the operation of a single syphon, the suction limb of which is located within a control chamber.

In this case, a control chamber 56 is as before connected by a conduit 26a to the float (not shown) and by an inlet pipe 57 to the body of water in the weir. A single syphon 58 having an air inlet or priming vent 59 is arranged with its suction limb 60 within the control chamber 56. Located within the control chamber 56, and close to the bottom thereof is a float lever 61 fulcrumrned at 62 and having a float 63 attached to one arm thereof and a valve 64 attached to the other arm, which valve is arranged to co-act with the bottom open end of the suction limb 60 of the syphon 58 in such a manner that when the water level in control chamber 56 falls sufliciently to expose the float 63, it by its weight will raise the valve 64 to close the bottom end of the suction limb 60. Due to the level of the conduit 26a where it enters the control chamber 56, being above the float assembly and above the bottom end of the suction limb 60, this action will only take place after the float has been drained by the action of the syphon 58. When fully open the capacity of the syphon 58 is substantially greater than to the inflow though the water inlet conduit 6a from the weir. The apparatus is designed so that the inflow through the inlet 57 will be balanced by the adjusted outflow through the syphon 58. The level inside the control chamber will therefore remain more or less constant, that is at a level just below the point of entry of the conduit 26a. This condition will be maintained as long as the water level in the weir remains above the priming vent 59 of the syphon 58. Should the level of Water in the weir fall sufficiently to uncover the priming vent 59, air will enter the syphon 58 and it will cease operating. The water level in the control chamber 56 will then rise and water from it will flow into the float via the conduit 26a, thereby causing it to sink and close the gate.

By providing a separate control chamber it is easier to arrange for effective screening of the water which passes through the syphons and past the valves. It also provides greater flexibility in the locating of the control apparatus which need not necessarily be placed alongside the gate.

Although the invention has so far been described as regards its application to a radial gate, it will be understood that it may equally well be applied to control a drum gate or sector weir. In this case, access to the inside thereof for syphon pipes, air vents and the like can be provided by way of a tubular axis member.

The invention, with modifications, could also be adapted to control a hinged shutter type of gate. The invention could also be adapted for the automatic operation of scour sluices for wasteways, for maintaining constant upstream or downstream levels in a canal system or for limiting the intake of trash and debris in rivers having a sporadic flow.

The method according to the invention provides for great flexibility in the operation of a gate by the provision of the following modification:

(a) By providing for adjustment of the flow through the water inlet aperture 6, 6a or 30 by means of either a manually adjustable valve or by means of an automatic constant delivery valve.

(b) By adjusting the vertical position of the secondary syphon priming vent 13 or 13a.

(c) By providing valve means to vary the air flow through the priming vent 13 or 13a.

(d) By adjusting the delivery of the secondary syphon by means of a simple valve or tap, or an automatic valve operated by upstream pressure.

(e) By the provision of simple ball and float valves in the float chamber so as to make it possible to adjust its buoyancy in order to provide a constant discharge to a canal, irrespective of the head of water in the weir.

(f) By providing shut-off stop cocks on both syphons enabling the gate to be kept closed for as long as required.

Another alternative arrangement is to place the pivot axis of the radial gate 3 on the upstream side and to arrange for a triangular float to be located between the supporting struts of the gate. The several pipes for the syphons, air vents and the like would then be arranged to pass through the axis of the gate. The gate would then be a modified form of drum gate. In this case, the level of the pivoting-axis would have to be raised to permit discharged water to flow beneath the float.

Although in the drawings the float 5 is shown actually attached to the upstream side of the gate 3, it may of course be arranged separate from it with connection be tween it and the gate being provided by the axis shaft 4. In this way more than one gate may be operated from a single float or alternatively more than one float may be arranged to operate a single gate. In these cases the gate may be of any of the well known forms of obturating devices used for irrigtion and like purposes. In the case of a vertically sliding shutter gate, a rack and pinion mechanism may be used to connect the float pivot shaft to such gate.

I claim:

1. Improved apparatus for the automatic regulation of the outflow from an open body of water impounded by a barrier and having a varying level when the level of said body of water is below a predetermined upper limit, which apparatus comprises a gate contiguous to said body of water and arranged to be opened and closed to control the outflow of water from said impounded body of water, a hollow float coupled to said gate on the side of said gate facing said body of water, said float having a water inlet adjacent the bottom thereof and having an air vent at the top thereof, conduit means connected to and opening out of the float and discharging downstream of said barrier, and control means in series with said conduit means for control of withdrawal of water from said float and discharging it downstream of the barrier at varying controlled rates so as to vary the buoyancy of the float and consequently the opening and closing movements of the gate, said control means being operatively dependent on the level of the impounded body of water, wherein the control means comprises a main syphon operable for said withdrawal and discharge of water, said syphon having a throat and air inlet means for syphon breaking purposes connected to the throat of said syphon means, said air inlet means being fixed in the impounded body of water below said predetermined upper limit to be covered or'uncovered depending on the level of the impounded body of water.

2. Apparatus as claimed in claim 1 in which said control means is fixed in said impounded body of water and said conduit means extends from the bottom of said float to the intake end of said syphon means and from the discharge end of said syphon means to the downstream discharge position.

3. Improved apparatus as claimed in claim 1 wherein the gate is of the radial type.

4. Improved apparatus as claimed in claim 1, wherein stop means are provided to limit the extent to which the float will rise and consequently thereby to limit the maximum outflow of water past or beneath the open gate.

5. Improved apparatus as claimed in claim 1, wherein said control means also includes a secondary syphon, said main syphon and having a discharge capacity when primed which is capable of removing water from the float at a rate in excess of the inflow capacity of the water inlet adjacent the bottom of said float, so as thereby to cause rapid emptying of the float notwithstanding the continued inflow of water through said Water inlet means, a secondary syphon having a discharge capacity which is substantially equal to the inflow capacity of the water inlet adjacent the bottom of the float, the end of the suction limb of the secondary syphon terminating closer to the bottom of the float than the end of the suction limb of the main syphon, whereby under certain circumstances, the secondary syphon will continue operating after the main syphon has stopped operating.

6. Improved apparatus as claimed in claim 5, wherein the air vent in the top of the float has a water inlet capacity substantially greater than the combined capacities of both syphons.

7. Improved apparatus as claimed in claim 5, wherein each syphon has an air inlet means and the air inlet means of the main syphon has its opening slightly below the corresponding opening of the air inlet of the secondary syphon, whereby a rising of the level of water in the weir causes the main syphon to prime before the secondary syphon.

8. Improved apparatus as claimed in claim 7, wherein the two syphons are mounted on the gate to rise and fall with the float.

9. Improved apparatus as claimed in claim 8, wherein the throats of the two syphons are below their respective air inlet means when the float is in its lowest position.

10. Improved apparatus for the automatic regulation of the outflow from an open body of Water impounded by a barrier and having a varying level when the level of said body of water is below a predetermined upper limit, which apparatus comprises a gate contiguous to said body of water and arranged to be opened and closed to control the outflow of water from said impounded body of water, a hollow float coupled to said gate on the side of said gate facing said body of water, said float having an air vent at the top thereof, conduit means connected to and opening out of the float and discharging downstream of said barrier, and control means in series With said conduit means for control of withdrawal of Water from said float and discharging it downstream of said barrier at varying controlled rates so as to vary the buoyancy of the float and consequently the opening and closing movements of the gate, said control means being operatively dependent on the level of the impounded body of water, wherein the control means comprises an open control chamber having a Water inlet in the bottom thereof in communication with the impounded body of water, the said conduit opening into the bottom of said control chamber, and at least one syphon having a throat, said syphon having the intake side in said control chamber and the discharge side opening into said conduit and discharging downstream thereof, and said syphon having air inlet means fixed in the impounded body of water below said predetermined upper limit to be covered or uncovered depending on the level of the impounded body of water.

References Cited by the Examiner UNITED STATES PATENTS 280,051 6/1883 Lyell 61--22 X 682,480 9/ 1901 Meyssonnier 61-22 2,207,479 7/ 1940 Danel 6125 2,984,986 6/1961 Hill 61-28 FOREIGN PATENTS 47,676 3/ 1937 France. 258,285 4/ 1928 Italy.

9,416 8/ 1923 Netherlands.

References Cited by the Examiner Irrigation Engineering, by Ivan E. Honk, vol. II, pages 262, 263.

Handbook of Applied Hydraulics, by Calvin Victor Davis, 2nd Ed., pages 270271.

Design Standard No. 3, Canals and Related to Structures Figure, Paragraph 7, 5B, by the United States Bureau of Reclamation.

CHARLES E. OCONNELL, Primary Examiner.

WILLIAM I. MUSHAKE, EARL J. WITMER, JACOB L. NACKENOFF, Examiners, 

1. IMPROVED APPARATUS FOR THE AUTOMATIC REGULATION OF THE OUTFLOW FROM AN OPEN BODY OF WATER IMPOUNDED BY A BARRIER AND HAVING A VARYING LEVEL WHEN THE LEVEL OF SAID BODY OF WATER IS BELOW A PREDETERMINED UPPER LIMIT, WHICH APPARATUS COMPRISES A GATE CONTIGUOUS TO SAID BODY OF WATER AND ARRANGED TO BE OPENED AND CLOSED TO CONTROL THE OUTFLOW OF WATER FROM SAID IMPOUNDED BODY OF WATER, A HOLLOW FLOAT COUPLED TO SAID GATE ON THE SIDE OF SAID GATE FACING SAID BODY OF WATER, SAID FLOAT HAVING A WATER INLET ADJACENT THE BOTTOM THEREOF AND HAVING AN AIR VENT AT THE TOP THEREOF, CONDUIT MEANS CONNECTED TO AND OPENING OUT OF THE FLOAT AND DISCHARGING DOWNSTREAM OF SAID BARRIER, AND CONTROL MEANS IN SERIES WITH SAID CONDUIT MEANS FOR CONTROL IT DOWNSTREAM OF THE BARRIER AT VARYING CONTROLLED CHARGING IT DOWNSTREAM OF THE BARRIER AT VARYING CONTROLLED RATES SO AS TO VARY THE BUOYANCY OF THE FLOAT AND CONSEQUENTLY THE OPENING AND CLOSING MOVEMENTS OF THE GATE, 